To prevent severe damage to biological samples during energy loss analysis it is necessary to scan the electron beam over the sample in a scanning transmission electron microscope. However, if the beam is scanned over the sample, the beam is also scanned over the entrance of the energy loss analyzer which produces unusable results. Therefore, a circuit has been built which descans the beam after it has passed through the sampel and keeps the beam stationary at the entrance of the energy loss analyzer from magnifications of 1000 to 100,000.